JPH0938759A - Die casting method and die device for die casting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately control the pressure and the quantity of a metallic material filled up into a cavity. SOLUTION: A shifting body 46 is shiftable to a base body 38 of a fixed die 32 and both dies are clamped with weak die clamping force and the metallic material is filled up into the cavity 34. In case of continuing a supply of metallic material from a die casting machine, the base body 38 and the shifting body 46, a movable die 33 are opened a little by the pressure of metallic material. By this method, fluctuation of the metallic material quantity from the die casting machine is absorbed and the pressure of the metallic material in the cavity 34 is made to a constant. Successively, the die clamp is executed with the intense die clamping force to close the base body 38 and the shifting body 46, and according with this, a part of the metallic material in the cavity 34 is returned back to the die casting side. The projecting part 58 of the base body is fitted to the recessed part 64 of the movable die 33 and at the point of time when a gate 67 is closed, the fixed quantity of the metallic material is remained into the cavity 34 and thereafter, the metallic material in the cavity 34 is compressed. By this method, the metallic material in a runner 66 and an overflow part is unnecessary to cut off in the following work.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a die casting method for a metal material and a die casting die apparatus.

[0002]

2. Description of the Related Art In die casting, a molten metal material is filled in a product-shaped cavity formed in a mold, and the product is molded by cooling and solidifying the metal material.

FIG. 5 shows a conventional die casting die apparatus. In the figure, 1 is a fixed type, 2 is a movable type,
The fixed mold 1 and the movable mold 2 open and close each other. Then, between the fixed mold 1 and the movable mold 2 that are closed, a cavity 3, a runner 4 which is a runner, a gate 5 from the runner 4 to the cavity 3, an overflow portion 6, and a cavity 3 to an overflow portion. A vent path 7 to 6 is formed.

In die casting, after the mold is closed,
A molten metal material is supplied to a runner 4 from a material supply device such as an injection cylinder of a die casting machine, flows from the runner 4 through a gate 5 into the cavity 3, and is filled therein. At this time, gas such as air in the cavity 3 is discharged to the outside of the mold through the vent path 7 and the overflow section 6. Then, as indicated by a chain line in FIG. 5B, the metal material flows from the cavity 3 through the vent passage 7 into a part of the overflow portion 6.
After that, the metal material in the mold is cooled and solidified, and then the mold is opened, and the metal material in the cavity 3, that is, the product, is taken out together with the solidified metal material in the runner 4 and the overflow section 6. The metal material solidified in the runner 4 and the overflow portion 6 is cut out from the product by post-processing.

As described above, in the conventional die casting method, the metal material of the runner 4 and the overflow portion 6 must be processed by post-processing, which is troublesome. The vent passage 7 for removing the gas has a width that does not allow the metal material to enter, and there is a mold device that does not have an overflow portion, but the treatment of the metal material of the runner 4 is still necessary.

By the way, since the metallic material shrinks with cooling, even after the metallic material is filled in the cavity 3, for example, the metallic material is continuously supplied to the cavity 3 for a while by the pressurization by the material feeding device and the metallic material shrinks. It is necessary to make up for the metallic material in minutes.

Without the overflow section 6, in the conventional mold device, the volume of the cavity 3 is constant, so that the pressure and amount of the metal material filled in the cavity 3 are basically controlled on the die casting machine side. Will be determined by Therefore, if there is an error in the control on the die casting machine side,
As it is, an error occurs in the pressure and amount of the metal material filled in the cavity 3. In order to eliminate this error, precise control of the injection cylinder and the like can be considered, but there are various causes of the error, such as temperature and variations in the properties of the metal material itself. For example, there is a long runner from the injection cylinder to the cavity 3, but if there is an error that occurs in this runway, even if the injection cylinder is precisely controlled, the pressure of the metal material filled in the cavity 3 and There will be an error in the quantity. This error causes defects such as variations in product weight.

On the other hand, when the overflow portion 6 is provided, the excess metal material is discharged to the overflow portion 6, so that the pressure and amount of the metal material filled in the cavity 3 are further stabilized. However, as mentioned above,
Post-treatment of the metal material of the overflow section 6 is required.

[0009]

As described above, in the conventional die casting die apparatus, since the gate is always open, the metal material of the material passage portion such as the runner must be processed by post-processing. There was a problem to be solved. Further, since the volume of the cavity is constant, there is a problem that it is difficult to accurately control the pressure and amount of the metal material filled in the cavity, especially when the overflow portion is not provided. On the other hand, when the overflow portion is provided, there is a problem that the metal material of the overflow portion must be processed by post-processing.

The present invention is intended to solve such a problem, and it is a first object of the present invention to eliminate the need for insufficient filling and to eliminate the need for post-processing of the metal material in the material passage and the overflow portion. And A second object is to enable the pressure and amount of the metallic material with which the cavity is filled to be accurately controlled. A third object is to simplify the structure for degassing.

[0011]

In order to achieve the first object, a die casting method according to a first aspect of the present invention includes a plurality of mold bodies which are opened and closed to form a cavity between them when the molds are closed. A mold apparatus having a volume adjusting means for adjusting the volume of the cavity is used, and the gate from the material passage to the cavity is closed as the volume adjusting means reduces the volume of the cavity. Then, first, a filling step of filling the molten metal material supplied from the material supply device to the material passage into the cavity having the increased volume is performed. After this filling step, a volume step of reducing the volume of the cavity and returning the metal material in the cavity to the material supply device side until the gate is closed is performed. After the measuring step, the volume of the cavity is further reduced to a predetermined volume and a compression step of compressing the metal material in the cavity is performed.

According to a second aspect of the present invention, in the die casting method according to the first aspect of the present invention, in order to achieve the second object as well, the material feeding device supplies a cavity to the cavity between the filling step and the weighing step. By continuing to supply the metal material and increasing the volume of the cavity by an appropriate amount in response to this supply,
A pressure adjusting step for adjusting the pressure of the metal material in the cavity is added.

In order to achieve the third object, the die-casting die device according to the third aspect of the present invention includes a plurality of die bodies that are opened and closed to form a cavity between the die bodies when the die is closed. The mold body has a closing member that abuts against another mold body and closes it, and a compression member that slidably penetrates through the closing member to form a cavity, and the gate from the material passage to the cavity is A gas vent that is provided at a position closed by the compression member as the compression member moves in the direction of reducing the volume of the cavity and that allows gas to escape from the cavity to the outside is formed by the gap between the closing member and the compression member. It is a thing.

[0014]

In the die casting method according to the first aspect of the invention, after the metal material is filled in the cavity, the volume of the cavity is reduced by the volume adjusting means to close the gate, and the metal material remaining in the cavity and the material passage The metallic material is cut in the mold device. After that, the metal material is not supplied into the cavity from the material supply device, but the volume of the cavity is further reduced by the same volume adjusting means, and the metal material in the cavity is compressed, so that the metal material shrinks due to solidification. Will be compensated.

Further, in the die casting method according to the second aspect of the invention, in the pressure adjusting step subsequent to the filling step, the metal material is continuously supplied from the material supplying device to the mold device, but more metal material is contained in the mold device. Is supplied, the volume of the cavity is increased by the volume adjusting means. Thus, even if there is an error in the amount of molding material supplied from the material supply device, this error is absorbed and the pressure of the metal material in the cavity is adjusted to a constant value. On the other hand, the amount of metal material in the cavity is not constant when the pressure adjustment step is completed, but in the subsequent measurement step, as the volume of the cavity becomes smaller, the excess metal material in the cavity becomes the material. When returning to the feeder side and closing the gate, a certain amount of metallic material remains in the cavity. Thus, the pressure adjusting step and the measuring step accurately control the pressure and amount of the metallic material with which the cavity is filled.

A die casting die apparatus according to a third aspect of the present invention is for carrying out the die casting method according to the first and second aspects of the present invention, wherein the volume of the cavity is adjusted by the closing member and the compression member. It constitutes a volume adjusting means. That is, the volume of the cavity is adjusted by moving the compression member forming the cavity with respect to the closing member in a state where the closing member is abutted against another mold body and closed. Further, the gate is closed by the compression member as the compression member moves in the direction of reducing the volume of the cavity. Then, at the time of die casting, in the filling step, the gas escapes from the cavity to the outside by the gas vent formed by the gap between the closing member and the compression member that slidably penetrates the closing member.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below.
Description will be made with reference to FIGS. 1 to 4. This embodiment uses a hot chamber type die casting machine as shown in FIG. In FIG. 4, 11 is a material supply device,
In this material supply device 11, a pressurizing chamber 13 is provided in a heating and melting tank 12, and a nozzle 14 is provided at the tip of this pressurizing chamber 13. A plunger 16 of an injection cylinder 15 which is a hydraulic cylinder is slidably fitted in the pressurizing chamber 13.

Further, 21 is a mold clamping device, and this mold clamping device 21
Has a fixed side platen 22 and a movable side platen 23. The movable platen 23 is movable in the left-right direction in the figure along the tie bar 24, and the hydraulic cylinder 25
Driven by the toggle mechanism 26. The drive of the hydraulic cylinder 25 is controlled by a drive control device 27 including a servo valve and the mold clamping force can be adjusted. Then, the fixed mold 32 of the mold device 31 is attached to the fixed platen 22, and the movable mold 33 is attached to the movable platen 23. The mold clamping device
The material supply device 21 and the material supply device 11 are comprehensively controlled by a control device such as a computer.

Next, the structure of the mold device 31 will be described with reference to FIGS.
It will be described in detail based on. In FIGS. 1 and 2, what is shown by thick line hatching is a metal material such as a zinc alloy or an aluminum alloy, which is a product. The fixed mold 32 and the movable mold 33, which are a pair of mold bodies, open and close each other by the movement of the movable platen 23, and form a product-shaped cavity 34 between them when the molds are closed.
The product P to be molded has a disk shape, and its axial direction is aligned with the mold opening / closing directions of the fixed mold 32 and the movable mold 33.

The fixed die 32 has a fixed side mounting plate 36 attached to the fixed side platen 22 and a fixed side receiving plate 37 fixed to the surface of the fixed side mounting plate 36 on the movable die 33 side. The fixed-side mounting plate 36 and the fixed-side receiving plate 37 form a base body 38 that is a compression member. Further, a locating ring 39 and a sprue bush 40 are fixed to the fixed side mounting plate 36. This sprue bush 40 is connected to the nozzle 14 of the material supply device 11, and the inside is a sprue 41 which is a material passage,
It penetrates through the fixed-side receiving plate 37 and projects toward the movable die 33.

On the movable die 33 side of the fixed side receiving plate 37,
A moving plate 46, which is a closing member, is supported so as to be movable within a predetermined range in the mold opening / closing direction. For this support, a sleeve 50 fixed by a bolt 49 together with a stopper 48 on the movable die 33 side of the fixed side receiving plate 37 slidably penetrates the moving plate 46. The stopper 48 limits the maximum gap between the movable plate 46 and the base body 38, that is, the maximum opening amount by hitting the movable plate 46 from the movable die 33 side.
Further, the moving plate is moved by the spring 51 which is a biasing means sandwiched between the fixed side mounting plate 36 and the moving plate 46 in a compressed state.
46 is biased toward the movable die 33 with respect to the base 38.
The tip end of the sprue bush 40 is slidably fitted in a through hole 52 formed in the moving plate 46.

The base 38 has a fixed side mounting plate.
The pin 56 is fixed by being sandwiched between the 36 and the fixed-side receiving plate 37. The pin 56 penetrates the fixed-side receiving plate 37 and projects toward the movable die 33 side. , Moving plate 46
It is slidably fitted in a through hole 57 formed in the. The tip of the pin 56 forms a convex portion 58 that can project toward the movable die 33 side with respect to the moving plate 46.

The movable die 33 is a movable plate 46 of the fixed die 32.
It has a movable side mold plate 61 that abuts against and closes. For mutual guidance of the movable side mold plate 61 and the movable plate 46,
A guide pin 62 is fixed to the movable plate 46, and a through hole into which the guide pin 62 is slidably fitted is attached to the movable side mold plate 61.
63 are formed.

The fixed mold 32 is attached to the movable side mold plate 61.
A concave portion 64 into which the convex portion 58 is removably fitted is formed. The fitting surface between the convex portion 58 and the concave portion 64 forms a cylindrical surface parallel to the mold opening / closing direction. The final product-shaped cavity 34 is formed by the convex portion 58 and the concave portion 64. That is, the tip surface of the convex portion 58 forms one end surface of the product P, the bottom surface of the concave portion 64 forms the other end surface of the product P, and the inner peripheral surface of the concave portion 64 forms the outer peripheral surface of the product P. .
Then, the movable plate 46 of the fixed mold 32 and the movable mold plate 61 which are closed move relative to the base 38 of the fixed mold 32, whereby the volume of the cavity 34 is continuously changed. A volume adjusting means for adjusting the volume of the cavity 34 is configured.

Further, the movable plate 46 of the fixed mold 32 and the movable mold which are closed.
A runner 66 and a gate 67, which are material passages for communicating the sprue 41 with the cavity 34, are formed between the 33 and the movable side mold plate 61. On the surface of the movable plate 46 on the movable die 33 side, an annular recess 68 surrounding the protrusion 58 is formed. The recess 68 communicates with the runner 66, and forms a part of the runner 66 and a gate 67 from the runner 66 to the cavity 34. The gate 67 is closed by fitting the convex portion 58 of the fixed die 32 into the concave portion 64 of the movable die 33. The force of the spring 51 urging the moving plate 46 is set to a force that keeps the moving plate 46 and the movable die 33 in a closed state against the pressure of the metal material in the runner 66.

By the way, in the fixed mold 32, the base 38
The gap C between the outer peripheral surface of the pin 56 and the inner peripheral surface of the through hole 57 of the movable plate 46 is set to about 0.1 mm on the side of the movable die 33 facing the recess 68. The size of the gap C is set so that a molten metal material cannot enter but a gas such as air can pass through. Thus, the gas vent 71 that allows gas to escape from the inside of the cavity 34 to the outside through the gap C is provided.
Are formed.

Although not shown, the movable die 33 has
A protrusion mechanism is provided for ejecting the molded product P and the metal material solidified in the runner 66 upon mold opening and releasing the mold.

Next, the method of die casting will be described. In the heating and melting tank 12 of the material supply device 11, the metal material is always in a molten state by being heated.

The mold clamping device 21 first closes the fixed mold 32 and the movable mold 32 with a weak constant mold clamping force F1. At this time, FIG.
As shown in (a), the movable plate 46 of the fixed die 32 and the movable die 33 abut against each other and close. On the other hand, the base body 38 of the fixed mold 32 and the movable plate 46 are opened with the initial opening amount A1, but the stopper 48 is not in contact with the movable plate 46. That is, mold clamping force
F1 and the force G of the spring 51 are in balance. Further, the convex portion 58 of the fixed die 32 is not fitted in the concave portion 64 of the movable die 33,
The open gate 67 allows the runner 66 to communicate with the cavity 34 having a relatively large volume. In this state, by moving the plunger 16 of the injection cylinder 15 in the material supply device 11 forward, the nozzle from the pressurizing chamber 13
The molten metal material (molten metal) is injected into the sprue 41 of the mold device 31 via 14. This metallic material is filled from the sprue 41 into the cavity 34 through the runner 66 and the gate 67 (filling step). At this time, the gas is discharged from the inside of the cavity 34 to the outside through the gas vent 71 formed by the gap between the outer peripheral surface of the pin 56 of the base 38 of the fixed die 32 and the inner peripheral surface of the through hole 57 of the moving plate 46. It This gas is an open substrate 38
It goes out of the mold apparatus 31 through the gap between the moving plate 46 and the moving plate.

Subsequent to this filling step, the mold clamping force remains F1 and, in the material supply device 11, until it is detected that the plunger 16 has advanced to a predetermined position, or
The injection process is continued until the plunger 16 advances to the forward limit. That is, the supply of the metal material from the material supply device 11 to the mold device 31 continues, but the mold device is accompanied by it.
Due to the pressure of the metal material in 31 as shown in FIG. 1 (b), the hydraulic pressure is not closed against the mold clamping force F1 applied by the mold clamping device 21 to the base body 38 of the fixed mold 32. Moving board 46
And the movable die 33 is displaced in the opening direction. By increasing the volume of the cavity 34 by an appropriate amount in this way, the generated internal pressure is released. The expanded opening amount A2 between the base 38 and the moving plate 46 is determined by the balance between the pressure of the metal material in the mold device 31 and the mold clamping force. More specifically, mold clamping force F1
And the force G of the spring 51 and the force H of the metal material in the mold device 31 for retracting the moving plate 46 and the movable mold 33 determine the opening amount A2. The opening amount A2 becomes larger as more metal material is supplied into the mold device 31. In other words, even if there is an error in the amount of the metal material supplied from the material supply device 11, the error is absorbed by the change in the opening amount, and the pressure of the metal material in the cavity 34 is adjusted and becomes constant ( Pressure regulation process). Thus, the cavity 34
The pressure of the metallic material inside can be controlled accurately.

The force G of the spring 51 is slightly weakened by increasing the opening amount from A1 to A2, and the mold clamping force applied by the hydraulic cylinder 25 is slightly changed by pushing back the toggle mechanism 26 together with the movable mold 33. However, changes in the force G and the mold clamping force of these springs 51 are so small that they can be ignored. That is, the variation in the pressure of the metal material that balances the force G of the spring 51 and the mold clamping force, which changes according to the displacement of the movable plate 46 and the movable die 33, when the cavity of a constant volume is filled with different amounts of the metal material. It is much smaller than the variation in pressure that occurs in.

In the pressure adjusting step, the pressure of the metal material acting to open the base 38 of the fixed die 32, the movable plate 46 and the movable die 33 is parallel to the die opening / closing direction for the fixed die 32. Pressure on the substrate 38 in the direction. This is the pressure related to pressure regulation. On the other hand, in the mold apparatus 31 of the above-described embodiment, since the runner 66 is formed between the movable plate 46 and the movable die 33 of the fixed die 32, the base 38, the movable plate 46 and the movable die 33 are opened. The pressure of the metallic material acting like
Substrate 38 is covered approximately only in cavity 34 (precisely including sprue bushing 40). Therefore, the pressure is adjusted based on the cavity 34. On the other hand, the pressure of the metal material in the runner 66 is the same as the moving plate 46 and the movable die 33.
However, the force of the spring 51 resists the pressure of the metal material in the runner 66, and the moving plate 46 and the movable die 33
And are kept closed. This is the same in the next measuring step.

After the pressure adjusting step is completed, the mold clamping device 21 increases the mold clamping force to F2. As a result, the base body 38 of the fixed die 32 and the movable plate
46 and are closing. Along with this, the excess metal material in the cavity 34 of which the volume becomes smaller returns from the gate 67 which is still open to the runner 66, and the metal material in the mold device 31 becomes the pressure chamber 13 of the material supply device 11. Return to inside. The plunger 16 retreats accordingly. Then, as shown in FIG. 2A, when the convex portion 58 of the fixed die 32 starts to be fitted into the concave portion 64 of the movable die 33, the gate 67 is closed, and at this point, a certain amount of metal material is left in the cavity 34. Will remain (weighing process).

After the weighing process, as shown in FIG.
The base body 38 and the movable plate 46 of the fixed die 32 are closed until they abut each other, and accordingly, the volume of the cavity 34 is reduced to a predetermined volume. As a result, the metal material in the cavity 34 is pressurized and compressed (compression step). The compression amount B is
Opening amount A3 between the base 38 and the moving plate 46 at the end of the weighing process
be equivalent to.

At the time when the pressure adjusting step is completed, the volume of the cavity 34, that is, the amount of the metal material in the cavity 34 is not constant. However, in the subsequent weighing process,
As described above, when the metal material in the cavity 34 returns to the runner 66 and the gate 67 is closed, a certain amount of metal material remains in the cavity 34. Thus, the pressure adjusting process and the measuring process accurately control the pressure and amount of the metallic material with which the cavity 34 is filled.

By the way, in the mold apparatus 31, the runner is
Since the 66 is formed between the movable plate 46 and the movable plate 33 instead of the base 38 of the fixed mold 32, the runner can be used in the weighing process.
The volume of 66 does not change. Therefore, the metal material smoothly returns from the cavity 34 whose volume decreases to the runner 66, and the pressure of the metal material in the cavity 34 is reliably kept constant. Along with this, the mold closing operation can be speeded up.

Further, since the moving plate 46 is formed with the concave portion 68 surrounding the convex portion 58 and forming a part of the runner 66 and the gate 67, the cooling of the metal material in the vicinity of the gate 67 is delayed, which causes During the weighing process, the cavity 34 to the runner 66
The metal material returns more smoothly. On the contrary,
If there is no recess 68 and the gate is just a side gate, the metal material inside the cavity generally cools faster because the position near the dividing surface between the fixed mold and the movable mold advances faster. Since the cooling and solidification of the metal material of (1) also progresses relatively quickly, there is a risk that the metal material will not return smoothly from the cavity to the runner. It should be noted that in order to sufficiently bring out the effect of the recess 68, it is necessary to make the recess 68 large enough to match the thickness of the product P.

After the gate 67 is closed as the mold is closed, a compression process is performed and the metal material in the cavity 34 is compressed. However, in the measurement process, a certain amount of metal material is stored in the cavity 34 at a constant pressure. By being left, the compression is smoothly performed. After the gate 67 is closed, the metal material is not supplied from the material supply device 11 into the cavity 34, but the compression compensates the shrinkage of the metal material in the cavity 34 due to the solidification by cooling. Of course, the compression has an effect that the cooling time in the mold device 31 can be shortened.

After the metallic material in the cavity 34 is sufficiently cooled and solidified, the mold clamping device 21 opens the fixed mold 32 and the movable mold 33. Accordingly, the metal material in the cavity 34, that is, the product P, the runner 66, and the sprue 41.
The metallic material solidified inside first separates from the fixed mold 32. Then, by the ejection mechanism, the runner 66 and sprue
The metal material and the product P solidified in 41 are ejected and separated from the movable die 33. In addition, runner 66 and sprue
After the metal material and the product P solidified in 41 are taken out, the mold is closed again, and the above steps are repeated.

As described above, according to the configuration of the above-described embodiment, the pressure and amount of the metal material filled in the cavity 34 can be easily and accurately obtained by the pressure adjusting process and the measuring process performed in the mold device 31. Therefore, it is possible to obtain a highly accurate product P with stable quality and without variations in weight.

Further, in the mold apparatus 31, since the runner 66 is formed between the movable plate 46 of the fixed mold 32 and the movable mold 33, pressure adjustment is performed with the cavity 34 as a reference, and in the measuring process. The metal material inside the cavity 34 runs smoothly 66
By returning to (3), the pressure and amount of the metallic material filled in the cavity 34 can be controlled more accurately.

Further, the movable plate 46 is formed with the recess 68 that surrounds the convex portion 58 and forms a part of the runner 66 and the gate 67, so that the metal material in the cavity 34 can be made smoother during the weighing process. Can be returned to runner 66.

Since the metal material in the cavity 34 and the metal material in the runner 66 are cut by closing the gate 67, it is not necessary to cut the metal material of the runner 66 by post-processing. At the same time, as described above, since the pressure and amount of the metal material filled in the cavity 34 can be accurately controlled by the pressure adjusting process and the measuring process, the mold device 31 does not need an overflow portion,
There is no need for post-processing of the metal material in the overflow portion.

Further, since the gate 67 is closed and compressed by the volume adjusting means including the base 38 of the fixed die 31 and the movable plate 46, the structure of the die unit 31 can be simplified. Further, since the gas vent 71 is formed by the gap between the base 38 of the fixed mold 32 and the movable plate 46, the structure for degassing in the mold device 31 can be simplified, and the mold device 31 having a structure without waste. Can be By forming the gas vent 71 by the gap between the base 38 of the fixed die 32 and the moving plate 46 in this way, the metal material is less likely to flow than the resin material and the like, and the outer peripheral surface of the pin 56 of the base 38 and the moving plate. Even if the gap between the through hole 57 and the inner peripheral surface of the through hole 57 is set to about 0.1 mm, it is possible because the metal material does not enter here.

The present invention is not limited to the above embodiment, and various modifications can be made. For example,
In the above embodiment, the case of using the hot chamber type die casting machine has been described as an example, but a cold chamber type die casting machine may also be used. That is, various types of material supply devices are used. Also,
The mold clamping device is also of the toggle type as in the above embodiment,
Various types are used, such as a direct pressure type in which the piston of the hydraulic cylinder is directly connected to the movable platen. The drive source of the mold clamping device is not limited to the hydraulic cylinder, but may be an electric motor or the like.

Further, the mold device is not limited to that of the above embodiment. For example, as the urging means for urging the moving plate 46, an air cylinder or the like can be used instead of the spring 51. Further, in the above embodiment, the runner 66 and the gate 67 are formed between the fixed die 32 and the movable die 33,
It is not limited to this. For example, if the product shape permits, it is also possible to adopt a direct gate which is open in the fixed mold in the mold opening / closing direction toward the movable mold side.
In this case, the convex portion provided on the movable die may be fitted to the direct gate to close it.

The product to be molded is not limited to a disk-shaped product, and the present invention can be applied to the molding of various shapes such as a ring-shaped product or a more complicated product.

[0048]

According to the invention of claim 1, in the measuring step after the filling step, the volume of the cavity is reduced by the volume adjusting means to close the gate, so that the metal material in the material passage is processed by post-processing. No need. Further, after the measuring step, the volume of the cavity is further reduced by the same volume adjusting means to compress the metal material in the cavity, so that the shrinkage due to the solidification of the metal material after the gate is closed can be compensated, and the insufficient filling can be prevented. It never happens. further,
In the mold device, the closing of the gate and the compression are performed by the same volume adjusting means, so that the structure of the mold device can be simplified.

Further, according to the second aspect of the present invention, the pressure adjusting step of adjusting the pressure of the metal material in the cavity is performed by adjusting the volume of the cavity, and then the measuring step is performed. The pressure and amount of the metallic material to be filled can be easily and accurately controlled, and thus a product of stable quality and high precision can be obtained. Moreover, since it is not necessary to provide the mold device with the overflow portion, there is no need for post-processing of the metal material of the overflow portion.

According to the third aspect of the present invention, since the gas vent for releasing the gas from the cavity to the outside is formed by the gap between the closing member and the compression member, which constitutes the volume adjusting means of the cavity, the gas is used in the mold device. The structure for removal can be simplified.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a part of a die casting die apparatus showing an embodiment of the present invention, (a) showing a filling step and (b) showing a pressure adjusting step.

FIG. 2 is a sectional view of a part of the die casting mold device,
(A) shows the measurement step and (b) shows the compression step.

FIG. 3 is an enlarged view of the vicinity of the same cavity, (a) is a sectional view, and (b) is a front view of a fixed mold.

FIG. 4 is a side view showing a cross section of a part of the entire apparatus used for die casting.

5A and 5B show an example of a conventional die casting die apparatus, in which FIG. 5A is a sectional view and FIG. 5B is a front view of a movable die.

[Explanation of symbols]

 31 Mold device 32 Fixed mold (mold body) 33 Movable mold (mold body) 34 Cavity 38 Base body (compressing member) 46 Moving plate (closing member) 66 Runner (material passage) 67 Gate 71 Gas vent

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location // B29C 45/26 9268-4F B29C 45/26 45/56 9350-4F 45/56

Claims (3)

[Claims] 1. A plurality of mold bodies which are opened and closed to form a cavity between them when the mold is closed, and a volume adjusting means for adjusting the volume of the cavity. The volume adjusting means reduces the volume of the cavity. With the use of a mold device configured so that the gate from the material passage to the cavity is closed, a filling step of filling the molten metal material supplied from the material supply device to the material passage into the cavity having a large volume, After the filling process, the volume of the cavity is reduced and the metal material in the cavity is returned to the material supply device side until the gate is closed, and after this measurement process, the volume of the cavity is further reduced to a predetermined volume and the cavity is reduced. And a compression step of compressing the metal material in the die casting method. 2. The metal in the cavity is increased by continuing to supply the metal material from the material supply device to the cavity between the filling step and the measuring step and increasing the volume of the cavity by an appropriate amount in response to the supply. The die-casting method according to claim 1, wherein a pressure adjusting step for adjusting the pressure of the material is added. 3. A plurality of mold bodies which are opened and closed to form a cavity between them when the molds are closed, and one of the mold bodies abuts and closes another mold body, and the closure member slides. And a compression member that freely penetrates to form a cavity, and the gate from the material passage to the cavity is closed by the compression member as the compression member moves in the direction to reduce the volume of the cavity. The die vent mold apparatus, wherein the gas vent for escaping gas from the cavity to the outside is formed by a gap between the closing member and the compression member.